减氧空气驱注入井井筒管柱氧腐蚀试验研究  

Experimental Study on Oxygen Corrosion of Wellbore String in Injection Wells with Oxygen-Reducing Air Flooding

作　　者：潘建澎 史宝成[1] 张兴凯 伍丽娟[1] 张引弟[1] 纪国法[1] Pan Jianpeng;Shi Baocheng;Zhang Xingkai;Wu Lijuan;Zhang Yindi;Ji Guofa(School of Petroleum Engineering,Yangtze University)

机构地区：[1]长江大学石油工程学院

出　　处：《石油机械》2022年第5期91-97,共7页China Petroleum Machinery

基　　金：国家科学自然基金项目“油气/水蒸气扩散火焰碳烟生成化学动力学与作用机理研究”(51974033)。

摘　　要：减氧空气驱技术兼有气源广、成本低、可入微裂缝与基质的优点,是稠油致密低渗油藏高效开发的重要手段。为了明确不同注气方式对井筒管柱的氧腐蚀规律,采用失重法,结合金相显微镜研究了N80、J55和3Cr钢在纯注气和气水混注工况下的氧腐蚀行为。研究结果表明:当减氧空气含氧体积分数为5%时,可以较好地兼顾减氧成本与防腐要求;在纯注气工况下,氧的体积分数为5%时,3种钢材均属于轻微腐蚀(<0.025 mm/a),减氧空气驱成本可保持在一个较低的水准,能满足国内油田防腐标准(<0.076 mm/a);在气水混注工况下,3种钢材在气水混注工况的腐蚀速率远大于纯注气工况,钢材腐蚀较为严重,需采取缓蚀剂或防腐涂层等防腐措施。研究结果可为减氧空气驱高压注气过程中含氧体积分数的选定以及注气井井筒的腐蚀防护提供数据支撑。Oxygen-reducing air flooding technology has many advantages such as wide gas source,low cost,and permeable to micro-fractures and matrix,so it is important for efficient exploitation of tight and low permeability reservoirs.In order to clarify the law of oxygen corrosion of wellbore string in different modes of gas injection,the oxygen corrosion behaviors of N80,J55 and 3 Cr steels under pure gas injection and gas-water mixed injection were studied by means of weight loss method with metallographic microscope.The results show that when the oxygen content of oxygen-reducing air is 5%,the oxygen-reducing cost and the corrosion protection requirements can be well balanced.If pure gas is injected,when the oxygen content is 5%,all three steels are slightly corroded(<0.025 mm/a),which meets the domestic oilfield anticorrosion standard(<0.076 mm/a),and the cost for oxygen-reducing air flooding can be controlled at a low level.If gas-water mixture is injected,the corrosion rates of the three steels are much higher than those in the case of pure gas injection,and the three steels are subject to serious corrosion,so anticorrosion measures such as corrosion inhibitors or anticorrosive coatings are required.In the application of oxygen-reducing air flooding,the study results can provide some data support for selecting proper oxygen content in oxygen-reducing air during high-pressure gas injection as well as taking proper corrosion protection measures on gas injection pipe strings.

关 键 词：减氧空气驱 含氧体积分数 注气方式 氧腐蚀 井筒材料 

分 类 号：TE983[石油与天然气工程—石油机械设备]